Abstract : An ALR-46 Computer Graphics System (CGS) for the Electronic Warfare Division Engineering Branch Laboratory was designed and implemented. The system is composed of the ALR-46 Radar Warning Receiver; real time hardware monitor; PDP 11/34 computer; and two display devices, a Tektronix model 4027 CRT and a Digital Equipment Corporation (DEC) model VT-100 CRT. The ALR-46 test engineers at the Engineering Branch Laboratory were interviewed: their functional requirements were translated into a detailed set of hardware and software requirements. Structured Analysis Techniques were used to produce a structured specification for the system requirements. Yourdon and Constantine's Transform and Transaction Analysis techniques were used to develop module structure charts for the software design. The final software design phase translated the module structure charts into Warnier-Orr (W/O) diagrams. These were translated into operational software using DEC Pascal. The software was implemented and tested using a top down approach. The modules and data structures were designed to allow additional capabilities to be added to CGS with minimum impact on the current system.